Contact structure for electric switches



March 27, 1951 R. P. BALLOU ETAL 2,545,663

CONTACT STRUCTURE FOR ELECTRIC SWITCHES Filed July 14, 1948 2 Sheets-Sheet 1 2 I 33 INVENTORS 38a Eve/70rd f Bcfl/OU 62 85 00/7/6/ F Don/y 22 23 vBY g 176 HTTOH/VEY March 27, 1951 R. RBALLOU ETAL CONTACT STRUCTURE FOR ELECTRIC SWITCHES Filed July 14, 1948 2 Sheets-Sheet 2 INVENTORS P/chard F. [Scfl/ou Dame/ F Da/y 1 TTORNEY 3 contact structure is automatically releasably locked;

Fig. is a view on the line 5-5 of Fig. 2

Fig. 6 is a view similar to Fig. 2 showing another form of the invention, the stationary contact structure being omitted; Y

Figs. 7 and 8 are side and bottom views, respectively, of the latch member shown in Fig. 6;

Fig. 9 is a view similar to Fig. 4, showing the insulation carriage in the form of the invention illustrated by Fig. 6; and

Fig. is a perspective View of the, contact holder in the form of the invention illustrated in Fig. 6. 1" v As here shown (Fig. 1), the switch towhich the present invention relates comprises a, plurality of poles, each pole being of identical structure. Since the poles are of identical structure, the operation of a single pole I is sufficient to demonstrate the invention. of thisapplication.

Each of said poles comprises two stationary con-- tacts 2 and 3 to which are respectively connected the incoming and outgoing wires of its branch of the circuit. Stationary contacts 2 and 3 are mounted upon a fixed block of insulating material A and serially spaced thereon sufficiently apart so as to prevent the establishment of a circuit by arcing. Fixed block of insulating material 4 is rigidly attached to a frame 5 for ,support thereby.

Bridge contact structure 6 through its bridge contact member .1 provides the means of bridging the gap between fixed contacts 2 and 3 to close the electrical circuit. Bridge contact structurefi shown in Fig. 2 is. mounted upon an insulated carriage 8 supported for displacement in a vertical direction by a suitable operating mechanism 9. Operating mechanism 9 may be either electrically or mechanically actuated. The

actuation of operating mechanism 9 brings bridge contact structure 6 into contact with fixed contacts 2 and 3 thereby bridging the gap to obtain the closure of the electrical circuit. Upon the release of operating mechanism 9, bridge contact structure 6 drops away from fixed contacts 2 and .3 for opening the electrical circuit.

Bridge contact structure 6 comprises bridge contact member I, helical spring I0, latch II, and holder I2 as shown in Figs. 2 and 3. Bridge contact member I comprises an elongated, prefer- 4 Latch II comprises horizontal body member 21 and the integrally connected downwardly projecting tongue 28 whose purpose will become subsequently apparent. Latch H sets loosely upon the upper surface of bottom member I9 of holder I2 in such manner that tongue 28 projectsth'rough slot 26 of said holder. In order to maintain latch II in position in holder l2 and yet permit the free movement of latch H about the back edge of bottom member I9 of holder I2 as a pivot, the side edges of horizontal member 21 are provided with rectangular notches 29 and 30 into which arms and M of holder I2, respectively, loosely fit. Midway between rectangular notches 29 and ill, the upper surface of member 21 is provided with a punched boss Bridge contact member I is supported on helical spring Ill one end of which fits around boss It of bar I3 and the other of which fits around boss SI of latch II. Bosses I6 and 3I,

thus hold spring I {I to prevent its movement outof position; Spring I0 yieldingly maintains bridge contact member 1 against the respective underfaces of abutments 2 3 and 25 of holder i2 thereby holding said bridge contact member in an elevated and operative position when the switch tacts 2 and 3 by the pressure of spring It;

ably rigid, metal bar I3 to whose top surface are rigidly secured oval faced contacts I4 and I5 at the respective ends thereof. Midway between contacts I4 and I5, the respective side edges of bar I3 are provided with identical rectangular notches I7 and I8 while the underside of said bar is provided with a circular boss I6 pressed therefrom. The supporting means for bridge contact member 1 comprises a holder I2 which has a horizontal bottom or' abutment member I9, the integrally connected spaced upstanding arms 20 and 2I adjacent one end thereof and lateral projections or fingers 22 and 23 near its other end. Arms 20 and 2 I, respectively, set loosely into notches I1 and I8 of bridge contact member 1 restrain movement of the latter in the direction of its length. The upperends of arms 2! and 2| are refiexed inwardly and constitute abutments 24 and 25, respectively, which overlie the upper face of contact member I at its intermediate portion and limit the outward position thereof. Approximately midway between arms 20, 2I and fingers 22, 23 along its longitudinal centerline, bottom member I9 of holder I2 is provided with a rectangular slot 26.

Bridge contact member 'I may be withdrawn from holder I2 by the vertical depression of said.

bridge contact member below abutments 24 and 25 suificiently to permit its being turned edgewise, about its longitudinal axis to permit the said bridge contact member to be withdrawn through the space between abutments 24 and 25. Spring IE] may remain in place, being held between latch II and abutments 24 and 25. In a reverse process of operation, bridge contact member I is inserted into holder I2 by turning said bridge contact member edgewise and depressing therewith spring I0 sufiiciently below the undersides of abutments 24 and 25 to permit the turning thereof into a horizontal position upon which attainment the said bridge contact memher is maintained inpositionby spring I0.

Insulated carriage 8 is provided with a rectangular recess 32 extending to the front face thereof, as shown in Figs. 2, 4 and 5, wherein the lower portion of bridge contact structure 6 is received, the fiat bottom 33 of said recess being wide enough to freely accommodate bottom member I9 of holder I2 but not wideenough to receive fingers 22 and 23. In order to permit holder I2 to be inserted in recess 32, the bottom portion of the front face of insulated carriage 8'is cut away providing rectangular recess 34 whose width freely accommodates fingers 22 and 23 and whose top surface 35 extends above the flat bottom 33 of recess 32 by an amount just sufficient to permit passage of the top surfaces of fingers 22 and 23. The front portion of the fiat bottom 33 of recess 32 is slightly inclined and recessed to facilitate the insertion of bridge contact structure 6 into position. Flat bottom '33 of rectangular recess 32 is provided with angular groove 36 whose purpose will become subsequently apparent.

The bridge contact structure comprising the above described assembly of contact member I,

ens

latch. II andspring, IIlin holder I2.may be read: ily placed in position in the companion recess 32, of carriage 8 and readily removed from the latter as a unit.

In order to insert the unitary bridge contact structure in position in the carriage 8, said structure is movedthrough the forward end of the companion recess 32 until the projections 22 and 23 engage the front surface portions 33! of carriage 8 at opposite sides of the recess above the surfaces 35 of front recess 34. Then the outer end of holder I2 is moved downwardly so as to bring projections 22 and 23 into registry with recess 34 below said surfaces 35, whereupon continued inward movement of the contact structure may be effected for disposing the latter in its operative position, with tongue 28 of latch II in catch-recess 36, with the inner end portion 40 ofsaid latch member projecting through inner end-opening 38 of recess 32, and with fingers 22 and'23 of holder I2 adjacent surface 31 of the front recess 35 of carriage member 8. It will be noted that the bent end portion 4 at the outer end of holder I2 provides a finger piece for fa cilitating the insertion and removal of the bridge contact structure. A guide groove 45, slightly wider than tongue 23, receives the latter during the inward movement of the contact structure unit i recess 32.

When it is desired to remove a bridge contact structure from'the carriage 3, pressure is exerted on. finger piece 44 of holder I2 for moving the latter a short distance inwardly in recess 32, to 'provide for clearance of tongue 28 from the forward end 35a of recess 35. While thestructure is in this inwardly displaced position, holder I2 is pivoted downwardly on the outer edge 45 of the bottom 33 of recess 32, with the result that the inner end 48 of holder I2 presses upwardly against latch I I against spring II]. During this movement of holder I2, the inner end portion A!) of latch II engages shoulder 42' adjacent its end 59 as a fulcrum about which said latch pivots, in a clockwise direction viewing Fig; 2, whereby the tongue of said latch is released from catch-recess 36. This allows the contact structure to be moved forwardly of recess 32 completely out of the latter.

The above described construction constitutes the presently preferred embodiment of the instruction as contact holder I2 but'is longer than the latter so that its rear part can. extends under the shoulder 52a of the insulation carriage 8d. The latch member Ila corresponds to latch member I I, but as here shown, latch member IIa has a stud 52 which is received in a. catch-recess 54 provided in the bottom 33a of the recess or groove 32a in which the contact structure is releasably mounted. As here shown, the peripheral wall of recess 54 is perpendicular to the bottom of recess 32a, so that when catch stud 52 is disposed in recess 54 the contact structure is locked against movement in recess 32a of the carriage, and so that latch member II a can be released only by positive movement thereof for withdrawing catch stud 52 from said catchrecess. It will be noted that. the slot 26a in holder 521a extends forwardly and that the latch. member I la is provided with a part 58 which extends through said slot and terminates in a forward free end portion 58 near the forward free.

end portionor finger piece 44a of. the contact holder IZa. When it is desired to remove the contact structure from the recess 32a of the carriage, end portions 44a and 58 of holder Ila and latch member II a respectively are gripped for pressing end portion 58 of latch member IIa toward holder I2a. Since shoulder 42a overhangs the end portion li-Ila of contact holder I2a, the pressure just referred to results in upward movement of the latch member He thereby withdrawing the catch stud 52 from the catch recess 54,. so that the contact structure can be removed from recess 32a through the front open end of the latter. In other respects, the contact structure shown in Figs. 6 to 10 is the same as the contact structure shown in Figs. 1 to 5 and the corresponding elements and parts. thereof are designated .by the same reference numerals respectively with the letter a added. It will be noted, however, that the rear end portion Ma of the latch member is flat and terminates short of the rear edge portion 48a of the contact holder I2a, so that the rear end of the latch member pivots on the upper surface of contact holder I2a when said latch member is operated, as herein- 'before described, for releasing the contact structure from the carriage 8a to permit the removal of said contact structure from said carriage. It will be understood that arms 20a and 2Ia of the contact holder I2a slidably engage the opposite side walls of the companion recess 32a and that fingers 22a and 23a of the contact holder are received under the surfaces 35a of the carriage in front recess 34a inthe same manner as the fingers 22 and 23 of holder I2, in front recess 34,, and it will be noted that when the fingers 22a and 23a are disposed below the surfaces 35a of said forward recess 34a, contact holder I2a is held positively at both ends against upward movement.

It will be apparent to those skilled in the art that a novel bridge contact structure for a contactor type of electric switch has been provided by the present invention which automatically locks and maintains itself upon a movable carriage without the necessity of other attaching elements. Such bridge contact structure providing at the same time for its contact member a resilient mounting rendering it capable of self alignment and adjustment thereby obtaining the proper contact surface with its related pair of stationary contacts.

Although but one embodiment of the invention has been illustrated and described in detail, various changes and modifications in the form and relative arrangement of parts which will now appear to those skilled in the art, may be made without departing from the scope of the inven tion.

Having. thus described our invention, what we claim and desire to secure by Letters Patent is:

1. A contact structure for an electric switch, comprising a contact bar provided with notches in its opposite side edges, a holder in which said contact bar is positioned for movement therein in opposite directions transversely of its length, said holder having parts which engage said bar in said notches for preventing movement said bar in the direction of its length, said holder hav ing reflexed confronting portions; reieasably engageable with said bar for limiting the move ment thereof in. one of said opposite directions, and spring means carried by said holder and yieldably holding said bar against movement in the'other of said opposite directions, said portions sagas being spaced from eachother for the edgewise passage of said bar .therebetween to effect the ready removal of said bar from said holder and the ready insertion of said bar therein, said spring means being retained in said holder by said portions when said bar is out of said holder.

2. A contact structure for an electric switch, comprising a contact bar provided with notches inits opposite side edges, a holder in which said contact bar is positioned for movement therein in opposite directions transversely of its length, said holder having laterally spaced arms which engage said bar in said notches for preventing movement of said bar in the direction of its length, said arms having inturned end portions which overlie said bar for limiting the movement thereof in one of said opposite directions, and spring means positioned between said arms and yieldably holding said bar against movement in the other of said opposite directions, said portions being spaced from each other for the edgewise passage of said bar therebetween to eiiect the ready removal of said bar from said holder and the ready insertion of said bar therein, said sprin s means being retained in said holder by said portions when said bar is out of said holder.

3. A contact structure for an electric switch, comprising a contact bar provided with notches in its opposite side edges, a holder in which said contact bar is positioned for movement therein in opposite directions transversely of its length, said holder having parts which engage said bar in said notches for preventing movement of said bar in the direction of its length, said holder having portions releasably engageable with said bar for limiting the movement thereof in one of said opposite directions, a latching member movably mounted in said holder and releasably engaging said switch for releasably holding said contact structure therein, and spring means hearing at its opposite ends against said bar and said latching member, respectively, for yieldably opposing movement of said-bar in the other of said directions and for yieldingly holding said latching member in position in said holder.

4. In an electric switch, an insulating supporting carriage, a contact holder having an abutment member in normal engagement with said carriage and spaced upstanding arms provided with inturned projections at the upper ends of said arms, a contact member located between said arms and in normal engagement with said projections, a latch member located between said arms, said latch member being in normal engagement with said abutment and in latching engagement with said supporting carriage; and spring means yieldingly holding said contact member in the aforesaid relation, said spring means also in collaboration with said latch constituting the means of locking said abutment member onto said supporting carriage.

5. In an electric switch, an insulating supporting carriage, a contact holder having an abutment member in normal engagement with said carriage and spaced upstanding arms provided with inturned projections at the upper ends of said arms, a contact member located between said arms and in normal engagement with said projections, a latch member located between said arms, said latch member being in normal engagement with said abutment and in latching engagement with said supporting carriage, and a spring bearing and releasably held upon said latch and against said contact member, said spring holding said contact member yieldably in position against said projections and also in collaboration with said latch constituting the means of locking said abutment member onto said supporting carriage.

6. In an electric switch, an insulating supportingcarriage having a rectangular recess therein, a contact supporting frame having a bottom member seated upon the bottom of said recess, spaced upstanding arms engaging the sides of said recess and extending above said carriage the said upper arms being provided with inturned opposed ends constituting abutments, and spaced horizontally projecting fingers extending beyond the sides of said recess, a second rectangular re-' cess in said supporting carriage extending sidewise beyond the said projecting fingers and providing bearing surfaces for the top faces of said projecting fingers, a contact member located between said arms and having its upper face bearing against said abutments, a latch member located within said arms, the front end thereof being in latching engagement with the bottom of the first recess and the back end thereof bearing upon the rear edge of the bottom member of said contact supporting frame, and spring means located within the space between the contact member and the latch and bearing against the underside of said contact member and also against the top side of said latch, said spring means yieldingly holding said contact member in the aforesaid relation and also in collaboration with said latch locking the contact supporting frame onto the said insulating carriage.

'7. In an electric switch, an insulating supportingcarriage having a rectangular recess therein, the bottom of said reces being provided with an angular groove, a contact supporting frame hav ing a bottom member seated upon the bottom of said recess, said bottom member beingprovided with an elongated slot, intergrally connected spaced upstanding arms engaging the sides of said recess and extending above said carriage, the said upstanding arms being provided with inturned opposed ends constituting abutments; and integrally connected spaced horizontally projecting fingers extending beyond the sides of said recess, a second rectangular recess in saidsupporting carriage extending sidewise beyond the said projecting fingers and providing bearing surfaces for the top faces of said projecting fingers, a contact member located within said arms and having its upper face bearing against said abutments, a latch member located within'said arms, comprising a downwardly projecting tongue and also a body, said tongue projecting downwardly through the elongated slot of the bottom member of said contact supporting frame into the angular groove of the bottom of the first rectangular recess and the said body bearing upon the upper rear edge of the bottom member of said contact supporting frame, and spring means located within the space between the contact member and the latch and bearing against the underside of said contact member and also against the top side of said latch, said spring means yieldably holding said contact member in the aforesaid relation and also in collaboration with said latch locking the contact supporting frame onto the said insulating carriage.

8. In an electric switch, an insulating supporting carriage having a rectangular recess therein, the bottom of said recess being provided with an angular groove, a contact supporting frame having a bottom member seated upon the bottom of 7 said recess, said bottom member-being provided gases g i9. with an elongated slot, integrally connected spaced upstanding arms engaging the sides of said recess and extending above said carriage, the said upstanding arms being provided with inturned opposed ends constituting abutments, and integrally connected spaced horizontally projecting fingers extending beyond the sides of said recess, a second rectangular recess in said supporting carriage extending sidewise beyond the said projecting fingers and providing bearing surfaces for the top faces of said projecting fingers, a contact member located within said arms and having its upper face bearing against said abutments, a latch member, located within said arms, comprising a downwardly projecting tongue and a body, said tongue projecting downwardly through the elongated slot of the bottom member of said contact supporting frame into the angular groove of the bottom of the first rectangular recess and said body bearing upon the upper rear edge of the bottom member of said contact supporting frame, and spring means located within the space between the contact member and the latch and bearing against the underside of said contact member and also against the top side of said latch, said spring means yieldably holding said contact member in the aforesaid relation and also urging said latch downwardly against the bottom member of said contact supporting frame and also into the angular groove of said first rectangular recess to prevent the horizontal displacement of said contact supporting frame thereby locking the said contact supporting frame onto the said insulating supporting carriage.

9. In an electric switch, a contact holder having opposed abutments, a contact member movably mounted within said holder, said contact member comprising end contact faces and an intermediate supporting portion having a bossed surface portion projecting from one side thereof, the opposite side of said intermediate supporting portion resting against the abutments of the contact holder, a latch member movably disposed within said holder having a bossed surface ortion projecting from one side thereof, said latch member releasably engaging said switch for releasably holding said contact holder therein, and a spring bearing against said contact member in a direction to maintain said contact member yieldingly against said abutments, said spring being releasably held at its opposite ends by encircling the projecting boss of the contact member and the projecting bossed surface of the latch.

10. In a switch, an insulation member having a recess, and a contact structure unit removably mounted in said recess, said contact structure comprising a holder, at contact member mounted in said holder, and a latching member carried by said holder and releasably engaging a part of said insulation member for releasably holding said contact structure unit in said recess, said holder having a part slidably abutting the bottom of said recess, part of the holder having an opening, and said latching member having a tongue projecting through said opening and having areleasable latching engagement with the bottom of said recess.

11. In a switch, an insulation member having a recess, and a contact structure unit removably mounted in said recess, said contact structure comprising a holder, a contact member mounted in said holder, and a latching member carried by said holder and releasably engaging a part of l0 said insulationmember for releasably holding said contact structure unit in said recess, said holder having a part slidably abutting the bottom of said recess, part of the holder having an opening, and said latching member having a tongue projecting through said opening and having a releasable latching engagement with the bottom of said recess, said contact member and said latching member being movably mounted in said holder in spaced confronting relation, and spring means disposed between said contact member and said latchingmember and yieldably holding them in their operative positions.

12. In a switch, an insulation member having a recess, and contact structure unit removably mounted in said recess, said contact structure comprising a holder, a contact member mounted in said holder, and a latching member carried by said holder and releasably engaging a part of said insulationmember for releasably holding said contact structure unit in said recess, said holder having a part slidably abutting the bottom of said recess, part of the holder having an opening, and said latching member having a tongue projecting through said opening and having a releasable latching engagement with the bottom of said recess, said contact member and said latching member being movably mounted in said holder in spaced confronting relation, and spring means disposed between said contact member and said latching member and yieldably holding them in their operative positions, said contact member and said latching member having notches in their opposite side edges and said holder having parts which engage said members in said notches for preventing movement of said members in the directions of their lengths, respectively.

13. In a switch, an insulation member having a, recess, and a contact structure unit removably mounted in said recess, said contact structure comprising a holder, a contact member mountedin said holder, and a latching member carried by said holder and releasably engaging a part of said insulation member for releasably holding said contact structure unit in said recess, said holder and said latching member terminating in forward free ends relatively movable toward each other at the front of said insulation member for releasing said latchingmember from said insulation member.

1a. In a switch, an insulation member having a recess, and a contact structure unit removably mounted in said recess, said contact structure comprisin a holder, a contact member mounted in said holder, and a latching member carried by said holder nd releasably engaging a part of said insulation member for releasably holding said contact structure unit in said recess, said recess having a frontiopening and said insulation member having a part at the rear end of said recess engageable by said holder, spring means resiliently pressing said holder and said latching member against each other and also releasably holding said latching member in engagement with said insulation member, said holder and said latching member terminating in forward free ends relatively movable toward each other at the front of said insulation member for releasing said latching member from said insulation member.

15. In an electric switch, an insulating supporting carriage, a contact holder having an abutment member in normal engagement with said carriage and spaced upstanding arms provided with inturned projections at the upper ends of said arms, a contact member located between said arms and in normal engagement with said projections, a latch member located between said arms and in normal engagement with said abutment and said supporting carriage, and spring means yieldingly holding said contact member in the aforesaid relation, said spring means also in collaboration with said latch constituting the means of locking said abutment member onto said supporting carriage, said abutment member of said contact holder having a rear part extending outwardly beyond said latch member and engageable with a part of said carriage, said contact holder and said latch member terminating in forward free ends relatively movable toward each other at the front of the carriage for releasing said latch member from said engagement thereof with said carriage.

RICHARD P. BALLOU. DANIEL F. DALY.

REFERENCES CITED UNITED STATES PATENTS I Number Name Date Koelln Dec. 20, 1927 Goetz Dec. 29, 1931 OKeefie Feb. 16, 1932 Yorger Mar. 1, 1932 Powell Apr. 22, 1941 Van Valkenburg Feb. 17, 1942 Pierce Mar. 17, 1942 Christensen July 25, 1944 Ballou Oct. 3, 1944 

